Association between KCNC1 gene polymorphisms and interindividual variability in aerobic capacity following high-intensity interval training.

OBJECTIVE: To explore the association between single nucleotide polymorphisms (SNPs) of the potassium voltage-gated channel subfamily C member 1 (KCNC1) gene and the improvement of aerobic capacity after high-intensity interval training (HIIT), and to screen potential genetic markers sensitive to HIIT. METHODS: A total of 249 Han college students (115 males and 134 females, aged 21.00 ± 0.07 years) were recruited and underwent 12 weeks of HIIT intervention, three times a week. Aerobic capacity indicators were measured before and after the intervention. Genotyping was performed using the Infinium CGA gene chip, and five KCNC1 gene SNPs were obtained after quality control with PLINK software. Linear regression models were used to analyze the association between SNPs and the training change values (Δ) of each indicator, with gender, age, height and baseline values as covariates. RESULTS: After 12 weeks of HIIT, VO2max/kg, VCO2, and VE significantly increased (P < 0.01). Submaximal heart rate during running economy (RE) assessment decreased significantly (P < 0.01), whereas maximal heart rate did not change significantly (P = 0.124). Association analysis revealed that three SNPs were significantly associated with training sensitivity: rs12574348 was suggestively associated with the Δ values of VO2max/kg (β = -0.9319, P = 0.048) and submaximal HR (RE, β = 3.069, P = 0.020), with CC-type subjects showing the greatest increase in VO2max/kg and the greatest decrease in submaximal HR (RE); rs757511 was suggestively significantly associated with the Δ values of VCO2 (β = 0.1076, P = 0.014) and maximal HR (β = 1.827, P = 0.048), with AA-type subjects showing the greatest increase in VCO2 and GG-type subjects showing the greatest decrease in HR_max; rs61882396 was suggestively significantly associated with the Δ value of VO2/kg (RE, β = -0.7673, P = 0.020), with AA-type subjects showing the greatest decrease in VO2/kg (RE). None of the above SNPs were significantly associated with baseline indicators (P > 0.05). CONCLUSION: The polymorphisms of KCNC1 gene rs12574348, rs757511, and rs61882396 are suggestively significantly associated with the improvement of aerobic capacity indicators after HIIT, and the effects are independent of baseline levels, suggesting potential involvement of KCNC1 in training-related neuromuscular adaptations, although the exact mechanisms remain to be established, thereby influencing individual sensitivity to HIIT. This gene may serve as a potential genetic marker for predicting the training effect of HIIT.